Quiz 4

Question 1

Aerobes

Answer 1

require oxygen

Question 2

Facultative anaerobes

Answer 2

can grow in the absence of oxygen but prefer the presence of oxygen

Question 3

Facultative anaerobes can obtain oxygen from alternative source such as ____

Answer 3

nitrate

Question 4

Anaerobes

Answer 4

cannot grow in the presence of oxygen because they lack the enzymes that take care of harmful products of oxygen metabolism

Question 5

microaerophiles

Answer 5

require free oxygen in small amounts

Question 6

capnophiles

Answer 6

microaerophiles that require elevated levels of carbon dioxide

Question 7

FTM ingredients

Answer 7

sodium thioglycollate
L-cystine
resazurin
agar
gelatin

Question 8

resazurin dye

Answer 8

pink in the presence of oxygen

Question 9

sodium thioglycollate and L-cystine function in FTM

Answer 9

reducing agents that reduce oxygen to water

Question 10

Gas generator sachet components in GasPak apparatus

Answer 10

sodium borohydride donates an H for O2 to form water in the presence of a palladium catalyst
sodium bicarbonate that produces CO2

Question 11

Gas Pak reaction

Answer 11

2H2 + O2 =(palladium)=> 2H2O

Question 12

Micrococcus luteus is yellow due to ____

Answer 12

carotenoid pigments

Question 13

cardinal temperatures

Answer 13

the range of temps a bacterium can grow at

Question 14

psychrophiles temp range

Answer 14

0-20C

Question 15

mesophiles temp range

Answer 15

15-45C

Question 16

thermophiles temp range

Answer 16

above 40C

Question 17

extreme thermophiles

Answer 17

65-110C; optimum 80C

Question 18

Serratia marcescens produces _________, a red pigment at _______ degrees C

Answer 18

prodigiosin; 25

Question 19

turgor pressure is maintained by

Answer 19

High K and Na ion concentration to promote inward diffusion of H2O
Compatible solutes made of amino acids

Question 20

halotolerant organisms

Answer 20

tolerate high salt, don’t require it
ex: Staphylococcus

Question 21

halophiles

Answer 21

require salt concentrations above 3%

Question 22

extreme halophiles

Answer 22

require 15%-25% salt

Question 23

osmophiles

Answer 23

require high concentrations of organic solutes (sugars)

Question 24

xerophiles

Answer 24

grow in environments with low water activity

Question 25

catalase test

Answer 25

tests for enzyme catalase which breaks down H2O2
positive: bubbles
negative: no bubbles

Question 26

Sugar fermentation tests

Answer 26

positive: yellow color change (acidic) and gas production indicated by bubble
negative: red color (basic) and no bubble

Question 27

nitratase test purpose and reagents

Answer 27

tests for the presence of nitrate and nitratase (converts nitrate to nitrite)
Sulfanic acid, dimethyl-alpha-naphthylamine, zinc

Question 28

Nitratase test results

Answer 28

positive: red color change at the beginning or no color change after zinc is added
negative: no color change initially; red color change when zinc was added

Question 29

methyl red test

Answer 29

tests for mixed acid fermenters upon glucose fermentation
positive: red color change
negative: yellow color

Question 29

voges-proskauer test purpose

Answer 29

tests for the production of alcohols (2,3-butanediol and ethanol) upon glucose fermentation, detects acetoin (precursor to 2,3-butanediol)

Question 30

KIA test

Answer 30

tests for glucose/lactose fermentation (phenol red), H2S production (iron salts), and gas production (air cracks/bubbles)

Question 31

voges proskauer test reagents and results

Answer 31

alpha-naphthol and KOH
positive: red color change
negative: yellow/brown color

Question 32

KIA test results

Answer 32

positive: yellow throughout the tube for lactose and glucose fermentation, yellow only in the bottom for glucose fermentation, dark precipitate if H2S forms, cracks if gas produces
negative: red throughout is no fermentation, red only in the bottom no glucose fermentation, no ppt and no cracks